ATLANTA -- As the Braves' top three relievers -- Craig Kimbrel, Jonny Venters and Eric O'Flaherty -- prepared for the start of the 2012 season, they shied away from being referenced as "The Untouchables," a nickname they gained while serving as Major League Baseball's best relief trio the previous season.

All of them essentially believed they needed to prove themselves over an extended period before earning such a title. Unfortunately, they were also in volatile roles, where it is hard to predict what tomorrow might bring.

One year later, Kimbrel is the only member of this vaunted trio who is still standing. Heavy workloads finally overwhelmed anatomical structures as Venters and O'Flaherty both underwent Tommy John elbow surgery over the past week.

"Who knows exactly what did what," said Braves pitcher Kris Medlen, who underwent Tommy John surgery in 2010. "But it's obviously just the wear and tear you get playing baseball your entire life."

There are countless questions surrounding the fact that Venters and O'Flaherty became the fifth and sixth pitchers to undergo this elbow ligament transplant procedure while pitching for the Braves over the past five seasons. Their heavy workload has been scrutinized over the past few years and they both were blessed with left-handed arms that were subjected to significant strain as they consistently threw 90-plus mph fastballs.

Some will argue the increase in Tommy John surgeries is a product of the extra wear and tear put on pitchers' arms while pitching nearly year-round on travel teams during their youth. But that argument does not fit the case of Brandon Beachy, who underwent the surgical procedure last year despite not pitching on a consistent basis before the Braves signed him late in the 2008 season.

"I don't have answers," Hall of Fame pitcher and current Braves broadcaster Don Sutton said. "Like many of you, I have a lot of questions. I don't know where to begin with the answers. I think what we're all trying to do is come up with a simple answer so that we can blame one thing. It's led to the pitch count and innings limitations. We're doing those things and the surgeries are increasing."

While totaling 756 starts and 5,282 innings over 23 Major League seasons, Sutton stood as a model of durability. Like many players of his generation, he is baffled by the amount of injuries incurred by today's starting pitchers, who have worked within the constraints of pitch counts and with the comfort of pitching once every five days.

But Sutton does sympathize with the toll placed on the arms of today's relievers, who have inherited the negative consequences of the fact that starting pitchers are not consistently working as deep into games as they did during his era.

During the 1970s, starting pitchers accounted for 72 percent of the innings completed by National League teams. That percentage has dropped as specialization and pitch counts have increased the significance of relief pitchers during the four decades that have followed. Last year, starting pitchers accounted for 66 percent of innings completed by NL clubs.

"Give the starters a little more responsibility," Sutton said. "Expect them to be better. Expect your starter to pitch the seventh and eighth innings. You're paying him a lot of money to do it."

The six percent decrease in innings completed by starting pitchers over the course of the past four decades might not seem like a lot. But it equates to approximately 85 innings per year per club. When factoring in the reality that three or four relievers are going to account for the brunt of this increased workload, a greater abundance of today's relievers are putting more stress on their arms than their predecessors.

"That's a lot to cover, when you figure you're covering it one inning at a time," Braves general manager Frank Wren said. "Even if it's spread over four guys, that's 20 more appearances each."

Venters struggled through three injury-plagued Minor League seasons after his first Tommy John surgery in 2005 and then finally proved healthy over entire season while making 29 starts for Triple-A Gwinnett in '09. The hard-throwing left-hander combined for 164 appearances with Atlanta over the next two seasons -- six more appearances than any other Major League pitcher during that span.

"What I got to do for those two or three years was awesome and I wouldn't trade it for anything," Venters said. "It's one of those things. It's part of the job and comes with the territory."

After making 276 appearances for Atlanta from 2009-12 -- seventh most in the Majors during this span -- O'Flaherty was left with a damaged elbow that progressively worsened as this season unfolded.

Another damaging aspect of the life of the reliever is not accounted for by statistics. As Medlen learned during his time as a reliever, there are numerous days when a pitcher warms up in the bullpen and never enters a game.

"It [stinks]," Medlen said. "It's like: 'Oh, he threw an inning yesterday, he's good today.' But the two days before that, I was up and I was about to go in the game. I was hot and I didn't go in the game. Then, I had to throw the next day."

Braves manager Fredi Gonzalez took a lot of heat when Venters (85), Kimbrel (79) and O'Flaherty (78) all ranked in the top five for appearances made during the 2011 season that ended with an epic September collapse. This workload was heavily influenced by the reality that the Braves played 26 extra-inning games and 55 one-run games that year.

Halfway through that season while his team was in Seattle, Gonzalez spoke about the need to be more selective about when to use his top three relievers. But at the end of the day, his decisions were most heavily influenced by what would give him the best chance to win a game.

"I still subscribe to the same theory that when it's your time to go, you're going to go," Gonzalez said. "But don't go out and play on [Interstate] 75. When it's time for your arm to blow, it's going to blow. But at the same time, you don't want guys throwing 190 pitches per outing. You've still got to take care of it."

While the Braves do not routinely run their pitching prospects to high pitch counts, Wren has told his Minor League managers over the past few years to take advantage of situations when they can push their young starting pitchers a little longer. The hope is that working through these late-inning situations will benefit the pitchers both mentally and physically.

"We want them to break through barriers, whether it's getting through the sixth, seventh or eighth [innings] or even finishing a game," Wren said. "Sometimes, just a matter of experiencing and feeling satisfaction of knowing that you've accomplished that is a big motivator to get guys to understand to pitch to contact, minimize pitch counts and get deeper into games."

A byproduct could be that these pitchers will work deeper into games once they reach the Majors and potentially prevent relievers like Venters and O'Flaherty from falling victim to the harsh demands placed on today's relievers.

"There's got to be more than meets the eye," Sutton said. "We've got more information, more conditioning, more medicines and more everything else. But we're having more surgeries than we ever had in the past. I don't have an answer, and I don't understand it."